mpm_netware.c

Apache 2.0.63 is the current stable version of the 2.0 series, and is recommended over any previous

                        listen state. */
                    if (!APR_STATUS_IS_EAGAIN(stat)) {
                        break;
                    }

                    if (wouldblock_retry--) {
                        apr_thread_yield();
                    }
                }
            }

            /* If we got a new socket, set it to non-blocking mode and process
                it.  Otherwise handle the error. */
            if (stat == APR_SUCCESS) {
                apr_socket_opt_set(csd, APR_SO_NONBLOCK, 0);
#ifdef DBINFO_ON
                if (wouldblock_retry < MAX_WB_RETRIES) {
                    retry_success++;
                    avg_retries += (MAX_WB_RETRIES-wouldblock_retry);
                }
#endif
                break;       /* We have a socket ready for reading */
            }
            else {
#ifdef DBINFO_ON
                if (APR_STATUS_IS_EAGAIN(stat)) {
                        would_block++;
                        retry_fail++;
                }
                else
#else
                if (APR_STATUS_IS_EAGAIN(stat) ||
#endif
                    APR_STATUS_IS_ECONNRESET(stat) ||
                    APR_STATUS_IS_ETIMEDOUT(stat) ||
                    APR_STATUS_IS_EHOSTUNREACH(stat) ||
                    APR_STATUS_IS_ENETUNREACH(stat)) {
                        ;
                }
                else if (APR_STATUS_IS_ENETDOWN(stat)) {
                       /*
                        * When the network layer has been shut down, there
                        * is not much use in simply exiting: the parent
                        * would simply re-create us (and we'd fail again).
                        * Use the CHILDFATAL code to tear the server down.
                        * @@@ Martin's idea for possible improvement:
                        * A different approach would be to define
                        * a new APEXIT_NETDOWN exit code, the reception
                        * of which would make the parent shutdown all
                        * children, then idle-loop until it detected that
                        * the network is up again, and restart the children.
                        * Ben Hyde noted that temporary ENETDOWN situations
                        * occur in mobile IP.
                        */
                        ap_log_error(APLOG_MARK, APLOG_EMERG, stat, ap_server_conf,
                            "apr_accept: giving up.");
                        clean_child_exit(APEXIT_CHILDFATAL, my_worker_num, ptrans, 
                                         bucket_alloc);
                }
                else {
                        ap_log_error(APLOG_MARK, APLOG_ERR, stat, ap_server_conf,
                            "apr_accept: (client socket)");
                        clean_child_exit(1, my_worker_num, ptrans, bucket_alloc);
                }
            }
        }

        ap_create_sb_handle(&sbh, ptrans, 0, my_worker_num);
        /*
        * We now have a connection, so set it up with the appropriate
        * socket options, file descriptors, and read/write buffers.
        */
        current_conn = ap_run_create_connection(ptrans, ap_server_conf, csd, 
                                                my_worker_num, sbh,
                                                bucket_alloc);
        if (current_conn) {
            ap_process_connection(current_conn, csd);
            ap_lingering_close(current_conn);
        }
        request_count++;
    }
    clean_child_exit(0, my_worker_num, ptrans, bucket_alloc);
}


static int make_child(server_rec *s, int slot)
{
    int tid;
    int err=0;
    NXContext_t ctx;

    if (slot + 1 > ap_max_workers_limit) {
        ap_max_workers_limit = slot + 1;
    }

    ap_update_child_status_from_indexes(0, slot, WORKER_STARTING, 
                                        (request_rec *) NULL);

    if (ctx = NXContextAlloc((void (*)(void *)) worker_main, (void*)slot, NX_PRIO_MED, ap_thread_stack_size, NX_CTX_NORMAL, &err)) {
        char threadName[32];

        sprintf (threadName, "Apache_Worker %d", slot);
        NXContextSetName(ctx, threadName);
        err = NXThreadCreate(ctx, NX_THR_BIND_CONTEXT, &tid);
        if (err) {
            NXContextFree (ctx);
        }
    }

    if (err) {
        /* create thread didn't succeed. Fix the scoreboard or else
        * it will say SERVER_STARTING forever and ever
        */
        ap_update_child_status_from_indexes(0, slot, WORKER_DEAD, 
                                            (request_rec *) NULL);

        /* In case system resources are maxxed out, we don't want
        Apache running away with the CPU trying to fork over and
        over and over again. */
        apr_thread_yield();

        return -1;
    }

    ap_scoreboard_image->servers[0][slot].tid = tid;

    return 0;
}


/* start up a bunch of worker threads */
static void startup_workers(int number_to_start)
{
    int i;

    for (i = 0; number_to_start && i < ap_threads_limit; ++i) {
        if (ap_scoreboard_image->servers[0][i].status != WORKER_DEAD) {
            continue;
        }
        if (make_child(ap_server_conf, i) < 0) {
            break;
        }
        --number_to_start;
    }
}


/*
 * idle_spawn_rate is the number of children that will be spawned on the
 * next maintenance cycle if there aren't enough idle servers.  It is
 * doubled up to MAX_SPAWN_RATE, and reset only when a cycle goes by
 * without the need to spawn.
 */
static int idle_spawn_rate = 1;
#ifndef MAX_SPAWN_RATE
#define MAX_SPAWN_RATE (64)
#endif
static int hold_off_on_exponential_spawning;

static void perform_idle_server_maintenance(apr_pool_t *p)
{
    int i;
    int to_kill;
    int idle_count;
    worker_score *ws;
    int free_length;
    int free_slots[MAX_SPAWN_RATE];
    int last_non_dead;
    int total_non_dead;

    /* initialize the free_list */
    free_length = 0;

    to_kill = -1;
    idle_count = 0;
    last_non_dead = -1;
    total_non_dead = 0;

    for (i = 0; i < ap_threads_limit; ++i) {
        int status;

        if (i >= ap_max_workers_limit && free_length == idle_spawn_rate)
            break;
        ws = &ap_scoreboard_image->servers[0][i];
        status = ws->status;
        if (status == WORKER_DEAD) {
            /* try to keep children numbers as low as possible */
            if (free_length < idle_spawn_rate) {
                free_slots[free_length] = i;
                ++free_length;
            }
        }
        else if (status == WORKER_IDLE_KILL) {
            /* If it is already marked to die, skip it */
            continue;
        }
        else {
            /* We consider a starting server as idle because we started it
            * at least a cycle ago, and if it still hasn't finished starting
            * then we're just going to swamp things worse by forking more.
            * So we hopefully won't need to fork more if we count it.
            * This depends on the ordering of SERVER_READY and SERVER_STARTING.
            */
            if (status <= WORKER_READY) {
                ++ idle_count;
                /* always kill the highest numbered child if we have to...
                * no really well thought out reason ... other than observing
                * the server behaviour under linux where lower numbered children
                * tend to service more hits (and hence are more likely to have
                * their data in cpu caches).
                */
                to_kill = i;
            }

            ++total_non_dead;
            last_non_dead = i;
        }
    }
    DBPRINT2("Total: %d Idle Count: %d  \r", total_non_dead, idle_count);
    ap_max_workers_limit = last_non_dead + 1;
    if (idle_count > ap_threads_max_free) {
        /* kill off one child... we use the pod because that'll cause it to
        * shut down gracefully, in case it happened to pick up a request
        * while we were counting
        */
        idle_spawn_rate = 1;
        ap_update_child_status_from_indexes(0, last_non_dead, WORKER_IDLE_KILL, 
                                            (request_rec *) NULL);
        DBPRINT1("\nKilling idle thread: %d\n", last_non_dead);
    }
    else if (idle_count < ap_threads_min_free) {
        /* terminate the free list */
        if (free_length == 0) {
            /* only report this condition once */
            static int reported = 0;

            if (!reported) {
                ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf,
                    "server reached MaxClients setting, consider"
                    " raising the MaxClients setting");
                reported = 1;
            }
            idle_spawn_rate = 1;
        }
        else {
            if (idle_spawn_rate >= 8) {
                ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf,
                    "server seems busy, (you may need "
                    "to increase StartServers, or Min/MaxSpareServers), "
                    "spawning %d children, there are %d idle, and "
                    "%d total children", idle_spawn_rate,
                    idle_count, total_non_dead);
            }
            DBPRINT0("\n");
            for (i = 0; i < free_length; ++i) {
                DBPRINT1("Spawning additional thread slot: %d\n", free_slots[i]);
                make_child(ap_server_conf, free_slots[i]);
            }
            /* the next time around we want to spawn twice as many if this
            * wasn't good enough, but not if we've just done a graceful
            */
            if (hold_off_on_exponential_spawning) {
                --hold_off_on_exponential_spawning;
            }
            else if (idle_spawn_rate < MAX_SPAWN_RATE) {
                idle_spawn_rate *= 2;
            }
        }
    }
    else {
        idle_spawn_rate = 1;
    }
}

static void display_settings ()
{
    int status_array[SERVER_NUM_STATUS];
    int i, status, total=0;
    int reqs = request_count;
#ifdef DBINFO_ON
    int wblock = would_block;
    
    would_block = 0;
#endif    

    request_count = 0;

    ClearScreen (getscreenhandle());
    printf("%s \n", ap_get_server_version());

    for (i=0;i<SERVER_NUM_STATUS;i++) {
        status_array[i] = 0;
    }

    for (i = 0; i < ap_threads_limit; ++i) {
        status = (ap_scoreboard_image->servers[0][i]).status;
        status_array[status]++;
    }

    for (i=0;i<SERVER_NUM_STATUS;i++) {
        switch(i)
        {
        case SERVER_DEAD:
            printf ("Available:\t%d\n", status_array[i]);
            break;
        case SERVER_STARTING:
            printf ("Starting:\t%d\n", status_array[i]);
            break;
        case SERVER_READY:
            printf ("Ready:\t\t%d\n", status_array[i]);
            break;
        case SERVER_BUSY_READ:
            printf ("Busy:\t\t%d\n", status_array[i]);
            break;
        case SERVER_BUSY_WRITE:
            printf ("Busy Write:\t%d\n", status_array[i]);
            break;
        case SERVER_BUSY_KEEPALIVE:
            printf ("Busy Keepalive:\t%d\n", status_array[i]);
            break;
        case SERVER_BUSY_LOG:
            printf ("Busy Log:\t%d\n", status_array[i]);
            break;
        case SERVER_BUSY_DNS:
            printf ("Busy DNS:\t%d\n", status_array[i]);
            break;
        case SERVER_CLOSING:
            printf ("Closing:\t%d\n", status_array[i]);
            break;
        case SERVER_GRACEFUL:
            printf ("Restart:\t%d\n", status_array[i]);
            break;
        case SERVER_IDLE_KILL:
            printf ("Idle Kill:\t%d\n", status_array[i]);
            break;
        default:
            printf ("Unknown Status:\t%d\n", status_array[i]);
            break;
        }
        if (i != SERVER_DEAD)
            total+=status_array[i];
    }
    printf ("Total Running:\t%d\tout of: \t%d\n", total, ap_threads_limit);
    printf ("Requests per interval:\t%d\n", reqs);
    
#ifdef DBINFO_ON
    printf ("Would blocks:\t%d\n", wblock);
    printf ("Successful retries:\t%d\n", retry_success);
    printf ("Failed retries:\t%d\n", retry_fail);
    printf ("Avg retries:\t%d\n", retry_success == 0 ? 0 : avg_retries / retry_success);
#endif
}

static void show_server_data()
{
    ap_listen_rec *lr;
    module **m;

    printf("%s\n", ap_get_server_version());
    if (ap_my_addrspace && (ap_my_addrspace[0] != 'O') && (ap_my_addrspace[1] != 'S'))
        printf("   Running in address space %s\n", ap_my_addrspace);


    /* Display listening ports */
    printf("   Listening on port(s):");
    lr = ap_listeners;
    do {
       printf(" %d", lr->bind_addr->port);
       lr = lr->next;
    } while(lr && lr != ap_listeners);
    
    /* Display dynamic modules loaded */
    printf("\n");    
    for (m = ap_loaded_modules; *m != NULL; m++) {
        if (((module*)*m)->dynamic_load_handle) {
            printf("   Loaded dynamic module %s\n", ((module*)*m)->name);
        }
    }
}


static int setup_listeners(server_rec *s)
{
    ap_listen_rec *lr;
    int sockdes;

    if (ap_setup_listeners(s) < 1 ) {
        ap_log_error(APLOG_MARK, APLOG_ALERT, 0, s,
            "no listening sockets available, shutting down");
        return -1;
    }

    listenmaxfd = -1;
    FD_ZERO(&listenfds);
    for (lr = ap_listeners; lr; lr = lr->next) {
        apr_os_sock_get(&sockdes, lr->sd);
        FD_SET(sockdes, &listenfds);
        if (sockdes > listenmaxfd) {
            listenmaxfd = sockdes;
        }
    }
    return 0;
}

static int shutdown_listeners()
{
    ap_listen_rec *lr;

    for (lr = ap_listeners; lr; lr = lr->next) {
        apr_socket_close(lr->sd);
    }
    ap_listeners = NULL;
    return 0;
}

/*****************************************************************
 * Executive routines.
 */

int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s)
{
    apr_status_t status=0;

    pconf = _pconf;
    ap_server_conf = s;

    if (setup_listeners(s)) {
        ap_log_error(APLOG_MARK, APLOG_ALERT, status, s,
            "no listening sockets available, shutting down");
        return -1;
    }